The rubber and plastic industries use screen type straining devices with restrictive holes to separate over size material from the process material. The restrictive holes progressively become plugged, causing an increase in the extrusion pressure, required to process the material. The progressive change in pressure requires additional input work per unit of material and thereby generates uneven temperature. The plastic industry has advanced to the extent that continuous screen changing devices are used to improve uniformity. The reclaim of vulcanized rubber products has been and is accomplished by warming the material and passing it through a rugged refiner mill which is set to an extremely small nip.